Would it be wrong to try to honor a murdered ancestor?

Wanting to acknowledge her doesn’t sound wrong to me. You could start with something simple and non-intrusive, like learning what you can about her life, saying her name, or making a remembrance that fits your own practice. You don’t have to invite possession or ask her to communicate in order to show respect.

If your culture has people you trust who understand these practices, ask them what would be appropriate. Traditions differ, and a grounded guide may help you avoid doing something that feels unsafe or disrespectful.

I’d be cautious about treating the curse explanation as established fact. A psychic’s interpretation can’t show that a spirit caused the family’s hardships, and difficult events can have many causes. You can take the history of her murder seriously without deciding that she is harming anyone.

If this is bringing up fear, it’s reasonable to pause contact attempts and focus on ordinary support for the living family. Remembering what happened and looking for reliable family records are meaningful options too.

Keep your boundaries clear. If you choose to do anything spiritual, decide beforehand what you are and aren’t comfortable with, and don’t let anyone pressure you into possession, risky rituals, or spending money to remove a supposed curse. You can stop whenever you want.

There’s no need to make this a test of whether you believe. A quiet act of remembrance can be enough, and choosing not to attempt contact is also a valid choice.